Loss of cortical GABA uptake sites in Alzheimer's disease

Abstract

[³H]Nipecotic acid bound to membranes of human brain in a saturable, reversible manner which was totally dependent on the presence of sodium ions. The potencies of compounds in inhibiting the specific binding of [³H] nipecotic acid were closely correlated with their potencies in inhibiting the neuronal uptake of [³H]GABA. Compounds selective for GABA receptors were inactive. [³H]Nipecotic acid appears to label neuronal high affinity GABA uptake sites. The binding of [³H]nipecotic acid was substantially reduced in the temporal cortex of brains from subjects with Alzheimer-type dementia, but not in other brain regions. It is concluded that some loss of GABA terminals occurs in this disease.